Inspection and repair of LED energy-saving lamps with obvious damage to the components

1. If the high-frequency transformer B is damaged, use ∮0.32mm high-strength wire to wind on the high-frequency magnetic ring of 10mm×6mm×5mm, T1 and T2 each have 4 turns; T3 is 8 turns (note the head and tail). Choke coil L: The lamp power is 5～40W, correspondingly between 1.5～5.5mH.

2. Although the fuse is not blown, the line at the incoming line is not blown and the resistance is obviously damaged, the transistor will be damaged undoubtedly. This may first be caused by the aging of the lamp, and secondly by the poor use environment, and may be caused by the loss of capacity of C1. For the first two cases, when replacing the resistors and transistors, it is best to also replace the matched C3 and C4 small electrolysis. For the latter, C3 and C4 do not need to be replaced. Because C1 works under high-voltage conditions, high-quality heat-resistant electrolytic capacitors must be used for replacement.

3. If only the resistance-capacitance parts and triode on the side of Q2 are burned out, check whether C2 has been broken down.

4. In the case of blown fuse and blown incoming line, if C1, Q1, and Q2 are intact, routine inspection and withstand voltage test must be carried out on D1～D4 one by one. Or replace all D1～D4 with high-quality products.

5. If C1 bursts, if it is accompanied by blown fuse or blown wire, all D1～D4 and C1 should be replaced.

A small number of electronic energy-saving lamps interfere with other household appliances

The inductance of L or the capacitance of C2 can be adjusted so that it does not interfere with the remote control TV and can work safely.

Maintenance of led energy-saving lamps that can’t light up normally

1. The magnetic cores of the choke coil L and the oscillating transformer B are broken. If you change the magnetic core alone, you should pay attention to three points:

(1) Use a magnetic core that meets the requirements, otherwise the inductance value of the choke may vary greatly, which will bury hidden dangers for energy-saving lamps;

(2) The magnetic gap cannot be too small to avoid magnetic saturation;

(3) After padding the magnetic gap with a suitable pad, stick it with an adhesive and wrap it with a high-temperature flame-retardant tape to prevent it from loosening. In addition, the end of the same name of B cannot be connected wrongly.

2. The lamp filament is open. If the lamp tube is not severely blackened, connect a 0.047μF/400V polyester capacitor to both ends of the broken filament lamp pin for emergency use.

3. R1 and R2 are open circuit or variable value (generally R1 is more likely to fail), replace it with a 1/4W high-quality resistor with the same resistance value.

4. For electronic ballasts that use trigger tubes, check the bidirectional trigger diodes. This tube is generally of type DB3, and its bidirectional breakdown voltage is 32±4V.

5. If the filament of a single low-power energy-saving lamp turns red or glows after it is lit, check D1～D4 for soft breakdown, whether C1 is installed reversely or leaking electricity, and whether there is a short circuit in the power supply.

6. The triode is open. If only one triode is found to be open, one cannot be replaced. Instead, a pair of matched switch tubes of the same model with a withstand voltage above 400V should be replaced. Otherwise, the lights will roll over or the tube will burn again.

7. It is common for the resonant capacitor C6 to break down (short circuit) or withstand voltage reduction (soft breakdown). It should be replaced with a high-quality polyester or CBB capacitor of the same capacity with a withstand voltage above 1kV.

8. The lamp is difficult to light up. Sometimes the light tube can be lit or the light rolls when touched by hand. This may be because the capacity of C3 and C4 is insufficient and not matched.

9. The lights flicker continuously. If the lamp tube is not severely blackened, check D5 and D6 for false soldering or open circuit. If D5 and D6 are softly broken down or the filter capacitor C1 is leaking or defective, the light will flash continuously.